The taurine upregulated gene 1 is abbreviated as “TUG1,” which is a spliced and polyadenylated RNA that was identified as non-coding RNA necessary for differentiation of rodents' retinas by Young et al. (Non-Patent Literature 1) and others, and TUG1 is expressed at a high level in tissues in the nervous system, such as retinal or brain tissues.
Concerning the roles of TUG1 in cancers or tumors, for example, cell growth is accelerated upon TUG1 knock-down in non-small cell lung cancer (NSCLC), as disclosed by Zhang et al. (Non-Patent Literature 2). In contrast, it has been reported that TUG1 is overexpressed in particular types of cancers or tumors and inhibition of TUG1 expression leads to inhibition of growth thereof. For example, Xu et al. (Non-Patent Literature 3) describes that TUG1 silencing leads to inhibition of esophageal squamous cell cancer (ESCC) cell growth and inhibition of cell cycle progression. Also, Zhang et al. (Non-Patent Literature 4) describes that TUG1 is overexpressed in osteosarcoma cell lines and that inhibition of TUG1 expression causes apoptosis of osteosarcoma cells. In addition, Han et al. (Non-Patent Literature 5) describes that TUG1 is overexpressed in urothelial cancer, TUG1 is correlated with an advanced clinical stage, and TUG1 silencing results in growth inhibition and apoptosis induction to the cancer.